1. Field of the Invention
The present invention relates generally to a mobile communication system, and more particularly to a mobile communication system, which supports text chatting, file transmission, and voice signal transmission among terminals through a real time information transmission service in a wireless network, without installing a separate system, and a messenger service-providing method using the mobile communication system.
2. Description of the Related Art
Currently, services provided by a code division multiple access (CDMA) mobile communication system have developed to include multicasting multimedia communication services through which both voice and a large amounts of data, such as packet data or circuit data, are transmitted. As a result, recently developed mobile communication terminals include performance capabilities and programs rivaling with those of personal computers. The improvement in portability and performance of the mobile communication terminal itself facilitates the use of supplementary functions by a user. Further, mobile communication terminals are store a large amount of data such as telephone numbers and personal schedules, which can be output or edited accordingly.
Additionally, mobile communication terminals have become personal effects of many modern persons, and users can exchange contact numbers with each other by exchanging one's own number of the mobile communication terminal with each other. This phenomenon has occurred because data storable in mobile communication terminals includes not only various telephone numbers but also the addresses and Internet mail addresses of users, even personal avatars.
Recently, a real time information transmission service program called “messenger” is being installed in a mobile communication terminal, thereby enabling an exchange of data between mobile communication terminals. Herein, the “messenger” service is a kind of real time information transmission service. The “messenger” service provides users with a full-duplex state in which users on both sides can simultaneously transmit a message to each other, similarly to telephone communication. This is an improvement over of the older half-duplex state in which a user cannot transmit a message while the other user on the counterpart side transmits another message, similarly to radio communication. In addition to the existing simple chatting, such a messenger service includes a multi-function, through which files, voice, and information such as a music or news may be transmitted.
FIG. 1 is a block diagram illustrating a conventional mobile communication system for providing a real time messenger service among mobile communication terminals. As illustrated in FIG. 1, mobile communication terminals 12, 14, 16, and 18 perform mutual mobile wireless communication among themselves through base stations 22, 24, and 26, and base station controllers 32 and 34. Herein, the base stations 22, 24, and 26 provide a mobile wireless network service to corresponding mobile communication terminals 12, 14, 16, or 18, and the base station controllers 32 and 34 control corresponding base stations 22, 24, or 26. Further, the mobile communication terminals 12, 14, 16, and 18 can exchange short messages with each other by means of a short message providing-service provided by a short message service (SMS) provider 52.
The existing mobile communication system for a real time information transmission service must include a separate messenger system in addition to the aforementioned communication network. Herein, the messenger system includes a messenger service subscriber data base (DB) 42 and a messenger server 44. The messenger service subscriber data base 42 stores operation state information for mobile communication terminals of subscribers receiving the messenger service, and list information about registered communication partners. The messenger server 44 manages the messenger service subscriber data base 42 and provides the real time messenger service to the mobile communication terminals 12, 14, 16, and 18.
Such a mobile communication system for the real time information transmission service uses a short message as a means for transmitting messages and control information among the mobile communication terminals 12, 14, 16, and 18. However, because the short message service provider 52 providing the short message service does not provide a short message service for interactive transmission among the mobile communication terminals 12, 14, 16, and 18, the message transmission causes a heavy load, which prevents the system from operating in real time. Further, the existing mobile communication system for the real time information transmission service has a disadvantage in that the system is limited to only the short message transmission among the mobile communication terminals 12, 14, 16, and 18.
Further, the messenger server 44 manages an operation state of each of the mobile communication terminals 12, 14, 16, and 18 when providing the messenger service to the mobile communication terminals 12, 14, 16, and 18, thereby causing an additional load. That is, the messenger server 44 calls the mobile communication terminals 12, 14, 16, and 18 in order to understand the operation state of each terminal. As a result, the wireless network is overloaded.